Synthesis and characterization of polyimide membrane for carbon dioxide removal prepared by dry-wet phase inversion method

Currently, membrane is a separation process that is gaining lots of attention in the industry, especially membranes for gas separation processes such as removal of carbon dioxide from natural gas. Among the available materials for these membranes, cellulose acetate has always been used as the conventional membrane polymer. In this paper, the focus was on polyimide, which was proposed to be the new alternative for cellulose acetate with certain distinguished advantages. As polyimide membrane is still a new material for membrane, this study focused on the detailed synthesis procedure of a flat sheet polyimide membrane through dry-wet phase inversion method. The chosen polymer was BTDA/ODA (Biphenyl Tetracarboxylic Dianhydride/ Oleoyl Diamine), along with DMF (Dimethyl Formamide) as solvent and a mixture of water/ethanol as non-solvents in coagulation bath. An addition of binder to the synthesis procedure was also tested in this paper. Characteristic tests were conducted to study about the morphology as well as the porosity of the membrane synthesis. In addition, some variations on membrane composition were conducted to study about the effect of polymer concentration, coagulation bath composition and binder addition on polyimide membrane. Lastly, a process optimization was done to choose the most suitable conditions and composition for the membrane synthesis.